The P0704 code appears in vehicles equipped with a manual transmission when the clutch pedal switch circuit sends an incorrect or missing signal to the ECM or TCM. It’s a common issue in Ford Focus, VW Golf, and Mazda3 models, where the clutch switch tells the car when the pedal is pressed—essential for starting the engine and for cruise control disengagement. If this circuit fails, your car may not start or may store a transmission fault.

Using a professional diagnostic scanner like the iCarsoft CR PRO S lets you test the clutch pedal switch signal in real-time, verify wiring integrity, and clear the stored DTC after repair.

🔍 What Does the P0704 Code Mean?

The P0704 Clutch Switch Input Circuit Malfunction means the ECM/TCM has detected an abnormal voltage reading from the clutch pedal switch circuit. This switch confirms the clutch is fully depressed before allowing the engine to start or the transmission to engage. In some cases, it can also affect idle stability or cruise control operation.

⚠️ Common Symptoms

• Engine won’t start unless the clutch pedal is pressed very hard
• Check Engine Light illuminated
• Cruise control not working
• Intermittent limp mode or no-start condition
• Inconsistent idle when clutch is engaged/disengaged

🔧 Common Causes of P0704

• Faulty clutch pedal switch
• Loose or damaged connector at the clutch switch
• Broken switch mounting bracket or misalignment
• Open or short circuit in wiring between switch and ECM
• Clutch switch stuck “open” or “closed” due to debris

🧰 How to Diagnose P0704 with iCarsoft CR PRO S

The iCarsoft CR PRO S can instantly detect if the clutch pedal switch is functioning by reading real-time sensor data. Follow these steps to diagnose and repair:

1. Connect the CR PRO S to the OBD-II port and turn the ignition ON (engine off).
2. Select your vehicle brand and navigate to the ECM or TCM system.
3. Enter Live Data and locate “Clutch Switch Status.”
4. Press and release the clutch pedal – you should see the data toggle between ON/OFF.
5. If no change occurs, inspect the switch connector for corrosion or loose pins.
6. Use a multimeter to confirm continuity through the clutch switch.
7. Replace the switch if it fails the continuity test and then clear the code.

🧠 Real Case: VW Golf 1.9 TDI with P0704

A VW Golf driver reported a P0704 code and a no-start condition. Using the iCarsoft CR PRO S, live data showed the clutch switch stuck in the “OFF” position even when pressed. Upon inspection, the switch plunger was broken due to pedal misalignment. After replacement and clearing the code, the car started normally and cruise control resumed operation.

💡 Pro Tips

• Clutch switches are inexpensive; replacing them often solves the problem quickly.
• Ensure the switch is properly seated—too loose or too tight can trigger P0704 again.
• If you see “P0704 after replacing clutch switch,” check wiring continuity to the ECM.
• Low voltage (see P0563) can cause false clutch input readings.

❓ FAQ: P0704 Code

• Can a faulty clutch switch prevent the car from starting?
  Yes, most manual cars won’t crank unless the clutch pedal switch confirms the pedal is pressed.
• Is P0704 dangerous to drive with?
  Usually not immediately dangerous, but can disable cruise control or cause intermittent starting issues.
• Will replacing the clutch switch clear P0704?
  After replacement, clear the stored DTC using the iCarsoft CR PRO S and confirm switch response in live data.
• Can this fault cause transmission limp mode?
  Occasionally, yes—especially in electronically controlled manual or automated clutch systems.

📘 Final Thoughts

The P0704 Clutch Switch Input Circuit Malfunction may seem minor, but it can completely disable starting or shifting if left untreated. With the iCarsoft CR PRO S, you can quickly pinpoint whether the clutch pedal signal is reaching the ECM, confirm live switch status, and restore proper operation in minutes.